Simple c# in memory cache. I have no idea if I built this or found it on the web somewhere. I find this interesting.

SimpleCache.cs

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Text;

namespace MajorSilence
{
    public class SimpleCache
    {

        static ConcurrentDictionary<string, (string value, DateTime expires)> _cache = null;

        public SimpleCache()
        {
            if (_cache == null)
            {
                _cache = new ConcurrentDictionary<string, (string value, DateTime expires)>();
            }
        }

        public void SetValue(string key, string value, TimeSpan expires)
        {
            if (expires.TotalSeconds == 0) return;

            _cache.AddOrUpdate(key, (value, DateTime.Now.AddMinutes(expires.TotalMinutes)), (k, o) => (value, DateTime.Now.AddMinutes(expires.TotalMinutes)));
        }

        public string GetValue(string key)
        {
            (string value, DateTime expires) outValue;

            _cache.TryGetValue(key, out outValue);


            if (!string.IsNullOrWhiteSpace(outValue.value))
            {
                TimeSpan span = outValue.expires.Subtract(DateTime.Now);


                if (span.TotalSeconds < 0)
                {
                    _cache.TryRemove(key, out outValue);
                    return null;
                }

                return outValue.value;
            }

            return null;
        }

    }

}